<p>Hello Stephen, Daniel and all.</p>
<p>Thank you very much for your candid comments and taking out time to respond to the issues I raised.</p>
<p>Even though it probably appears so, I am not just copying random pieces of code. The workshop builds on previous versions and I have tried to follow it as closely as possible and only make modifications based on the data I am working with.</p>
<p>I am not working with OSM data, instead I started with shapefiles loaded as a table (eastlegon) into a postgis database (which I named routing). My data is also entirely in ESPG 4326 and I am working from a windows machine but was able to install pgrouting easily using the installer at <a href="http://winnie.postgis.net/download/pg2/buildbot/postgis-bundle-pg92x32-setup-2.1.1-1.exe">http://winnie.postgis.net/download/pg2/buildbot/postgis-bundle-pg92x32-setup-2.1.1-1.exe</a> to my already existing PostgreSQL database. I loaded the data, added the additional columns, ran the topology function, added indices, ran queries using the algorithms (bearing in mind my table name) and I got results similar to the workshop.</p>
<p>All of this I fully understand and I've done it more than once just to be sure I am not making any mistakes so much that I can almost do it in my sleep. However, if you advise that I start again from scratch, create a database 'pgrouting-workshop', and table 'ways' instead of my existing setup, I will!</p>
<p>Everything works fine till I get to the wrappers part of the workshop. The one with link Daniel shared. I must admit, I've tried to understand the code, and I'm still working on it, and that's why it appears I simply copy it.</p>
<p>Two simple questions I now have are:<br>
1) Is there any existing resource that explains (as straightforward as possible) the basics of how to write a wrapper from scratch for a beginner like me?</p>
<p>2) Do I actually need to write custom wrappers (based on my dataset) to get my application to work? All I'm simply trying to do is create a simple application that allows users to set a start and end point, calculate route using at least dijkstra algorithm and display the results as a new layer, all in a web browser. If I do, how best do you advise I go about it. If not, how best can I build on the workshop to achieve my goal.</p>
<p>Thanks once again for your time. Without you guys and the work you've done I would not even know where to get started. I really appreciate.</p>
<p>Regards,</p>
<p>Emmanuel Adegboye</p>
<div class="gmail_quote">On Jan 10, 2014 1:18 AM, "Daniel Kastl" <<a href="mailto:daniel@georepublic.de">daniel@georepublic.de</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><br>
I tried running thr pgr_fromAtoB wrapper function in pgAdmin and I<br>
initially get an error:<br>
<br>
ERROR: relation "vertices_tmp" does not exist<br>
SQL state: 42P01<br>
Context: PL/pgSQL function pgr_fromatob(character varying,double<br>
precision,double precision,double precision,double precision) line<br>
11 at EXECUTE statement<br>
<br>
</blockquote>
<br></div>
I think Daniel will have to answer this. pgr_fromatob() must be a wrapper as that is part of the tutorial because it is not part of the pgrouting release.<div><br></div></blockquote><div><br></div><div>This is the function: <a href="http://workshop.pgrouting.org/chapters/wrapper.html#route-between-lat-lon-points-and-return-ordered-geometry-with-heading" target="_blank">http://workshop.pgrouting.org/chapters/wrapper.html#route-between-lat-lon-points-and-return-ordered-geometry-with-heading</a></div>
<div><br></div><div>As Steve mentioned, you will not be successful to copy pieces of code (randomly) without understanding what actually is going on there. </div><div><br></div><div>The workshop really tries to explain everything, and I don't think it makes sense to just copy the text from the link above. It should be all explained. If you're missing some information, or something is unclear, then feel free to ask.</div>
<div><br></div><div>Daniel</div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div> </div></div><div><br></div>-- <br><span style="font-family:arial,sans-serif;font-size:13px;border-collapse:collapse">Georepublic UG & Georepublic Japan<br>
eMail: <a href="mailto:daniel.kastl@georepublic.de" style="color:rgb(66,99,171)" target="_blank">daniel.kastl@georepublic.de</a><br>Web: <a href="http://georepublic.de/" style="color:rgb(66,99,171)" target="_blank">http://georepublic.de</a></span>
</div></div>
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